The present invention relates to an adjustable-length stick or adjustable-length pole, having at least a first and a second tube that telescope and are joined by a spreading element, of the type used in hiking poles or ski poles.
In an adjustable-length stick such as is known from DE 297 06 849 U1, the spreading element is provided with a tapering inner cone with an apex oriented towards an inner tube, whereas the corresponding interior element that is provided with the outer cone is displaced towards the inner tube by an adjusting screw so that the spreading device can grab hold. In this manner, although the result is a relatively parallel clamping over the entire axial length of the spreading element, nevertheless it has been found that in response to impact-like stresses on the stick tip from the handle-side of the adjustable-length stick, an axial displacement of the outer tube with respect to the inner tube cannot always be avoided and especially not when, in a twisting motion used to expand the spreading element, insufficient force has been applied for purposes of clamping.
Furthermore, from DE 297 08 829 U1, an adjustable-length stick is known, in which an interior element that is provided with an outer cone is formed by a forward free end of an adjusting screw, and a spreading element that is provided with an inner cone is moved axially on the adjusting screw. In this context, although the inner cone of the spreading element is opened towards the inner tube, nevertheless the same aforementioned disadvantages arise here if the spreading element is axially fixed in the spread-apart state. In this case as well, a relative motion between the outer tube and the spreading element can occur.
The objective of the present invention is to create an adjustable-length stick, especially for poles, of the species cited above, which, in response to impact-like axial stresses, continues to clamp rather than slide or give way.